Rifle Scopes Help selecting the Right Base

[Don-n-Texas]

LOL I need more help. Thank you to everyone one for their help in the past... present and future.

I need help in selecting the Right Base and understanding how to determine the right base for scopes.

100 yard zero

Rifle # 1 .308, 168 grains

Rifle #2 .223 AR-15 69 grain

Here is WHAT I THINK I know.

If a scope has 70 MOA of travel. It has 35 MOA up and 35 down. If you install a 20 MOA base.

Question #1 do you now have 55 MOA up and 15 MOA down? Am I right or wrong?

I understand the scope should be mounted as close to the rifle as possible.

If the distance from the center of the scope to the center of the rifle barrel changes from 2" to 2-1/2".

I think you would have to adjust downward to make up for rising the scope up. Am I right or wrong?

I don't think it would take very much adjustment. Am I right or wrong?

Question #2 At what point should I be concern about running out of downward travel in maintaining a 100 yard Zero.

Am I on the right track or should I take up Bowling. lol

Thank you everyone for your time and advice.

 

[Rugrat]

Re: Help selecting the Right Base

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Don-n-Texas</div><div class="ubbcode-body">LOL I need more help. Thank you to everyone one for their help in the past... present and future.

I need help in selecting the Right Base and understanding how to determine the right base for scopes.

100 yard zero

Rifle # 1 .308, 168 grains

Rifle #2 .223 AR-15 69 grain

Here is WHAT I THINK I know.

If a scope has 70 MOA of travel. It has 35 MOA up and 35 down. If you install a 20 MOA base.

Question #1 do you now have 55 MOA up and 15 MOA down? Am I right or wrong? <span style="color: #FF0000"> Yup, you got it!</span>

I understand the scope should be mounted as close to the rifle as possible. <span style="color: #FF0000"> Yup, you got it!</span>

If the distance from the center of the scope to the center of the rifle barrel changes from 2" to 2-1/2".

I think you would have to adjust downward to make up for rising the scope up. Am I right or wrong? <span style="color: #FF0000">Sorry, I don't understand this question.</span>

I don't think it would take very much adjustment. Am I right or wrong?

Question #2 At what point should I be concern about running out of downward travel in maintaining a 100 yard Zero. <span style="color: #FF0000">When hanging by your knees from the monkey bars in a futile attempt to shoot upside-down. LOL. In other words, never.</span>

Am I on the right track or should I take up Bowling. lol <span style="color: #FF0000">I actually drove past a bowling alley the other day and thought, "those poor bastards."</span>

Thank you everyone for your time and advice. </div></div>

You're on it. You want a 20 moa base unless your scope is very constricted with respect to adjustment travel. 70 moa is plenty and will really benefit from the 20 moa base when you get out to 1000 yards, since 35 moa may, or MAY NOT, get you to the prom. (note, however, that 168 grain bullets will not hold supersonic at 1K yards)

 

[Don-n-Texas]

Re: Help selecting the Right Base

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Rugrat</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Don-n-Texas</div><div class="ubbcode-body">

I think you would have to adjust downward to make up for rising the scope up. Am I right or wrong? <span style="color: #FF0000">Sorry, I don't understand this question.</span>

Thank you everyone for your time and advice. </div></div>

You're on it. You want a 20 moa base unless your scope is very constricted with respect to adjustment travel. 70 moa is plenty and will really benefit from the 20 moa base when you get out to 1000 yards, since 35 moa may, or MAY NOT, get you to the prom. (note, however, that 168 grain bullets will not hold supersonic at 1K yards) </div></div>

Thank you Rugrat

I don't think I understand that question either.

I got some 175's too.

 

[MattyG]

Re: Help selecting the Right Base

Yup 20 MOA for gaining the travel needed to get the reticle on target at long range, just make sure you can get the zero you want at 100 with the canted base. The last thing you want to do is handicap yourself into settling for a 200 or 300 yard zero because you have too much cant with a restrictive scope. Also 168's go transonic before 1000 yards in certain weather conditions.